1. Field of the Invention
This invention relates to a battery pack that detects case disassembly.
2. Description of the Related Art
User disassembly of the case or modification of a battery pack containing batteries and protection circuitry compromises safety and its prevention is necessary. To implement this, a tamper-prevention feature has been developed that attaches an external label to the surface of the case, and evidence of tampering remains if that label (seal) is broken (see Japanese Patent Application Disclosures 2003-68267, 2002-311836, and 2003-195767). Since the external labels cited in these patent disclosures leave evidence of tampering, they are useful in determining the root cause when a failure or customer-claim develops. Further, as a result of prior knowledge that the external label will leave evidence of tampering if broken, the label has the effect of suppressing the user's initiative to tamper and thereby is linked to tamper-prevention.